The production of sugar cane presents certain unique problems. To plant a new field today, the ground is prepared by initially breaking up the ground using a tractor with a ripper attachment, harrowing or leveling, and marking the ground for a planting machine to follow. The planting machine is generally a modified tractor with seedling and drip line laying attachments. The seed and drip line laying attachments may be pivotally attached to the machine such that the attachments may move laterally relative to the machine as the machine traverses the field. Specifically, a seed laying attachment includes one or more seed heads. The seed heads are pivotally attached to the seed laying attachment. The seedlings being planted are dispensed onto the ground through the seed heads. Drip lines are buried 1-3 inches below the surface between rows of plants and are used to deliver water and fertilizer to the plants. The seedlings are then covered with a thin layer of soil. To ensure the proper amount of water reaches the seedlings from the drip lines, a ripper shank is used to break up the hard pan to allow the water to drain away from the roots. Hard pan is hard soil that may lay several inches up to several feet below the surface. If the hard pan is not broken up, the water will accumulate on top of the hard pan and cause the roots to rot.
The field is then watered and fertilized via the drip lines and generally maintained for a period of two years before the initial harvest. Four months before harvest, the sugar cane plants are sprayed with a defoliant and the plants are no longer watered. The plants become stressed and begin ramping up sap production. The sap contains a high concentration of sugar. The leaves of the plants dry up while the stalks are filling with sap. The field is then burned to eliminate the bulk of the leaves, i.e., the non-sugar containing mass. This makes processing more efficient. The stalk which contains the sap is generally unaffected by the fire.
After the fire, the remaining plant stalks are dozed into wind rows by a harvesting machine. For example, a harvesting machine may include a tractor with a multi-shank rake attached to the front. The sugar cane stalks are intertwined and practically cover the ground, making identification of the original plant rows nearly impossible. By dozing, and then raking the field to harvest the stalks, the roots of the plant may become uprooted. Thus, the field may require partial replanting. To reduce the risk of uprooting, the harvesting machine is operated at a 45.degree. angle from the plant rows. This reduces the number of uprooted roots (root balls) but does not eliminate the problem.
Loading machines, for example modified hydraulic excavators with logging and grappling attachments, are then used to load the wind rows into haulage machines for transport.
After harvest, the sugar cane plants will normally grow back. However, if some roots or root balls were pulled out of the ground, the field may need to be partially replanted. Additionally, new drip lines will need to be laid because they are burned. However, immediately after harvest it is difficult to see the locations of the plant rows. Typically, laying of the drip lines is delayed 4-6 weeks until new plants begin to emerge, which allow the row locations to be seen.
Unlike a field such as a rice field, the terrain covered by the planting machine is not flat. A rice field is flat in order to provide proper irrigation when the fields are flooded. In contrast, a sugar cane field is not flat. There are several issues associated with developing a sugar cane field that are not addressed when a rice field is developed, because the sugar cane field is not flat. Guiding the harvesting or ripping machine along the same path that the planting machine traversed, without knowing the location of the seedlings, is not an adequate solution. A row of seedlings do not inherently lie in a straight line, and do not inherently follow the path of the planting machine. For example, the location of seedlings may deviate 3 to 6 inches from side to side, within a row. Deviations may occur for example, if the planting machine traverses a rock causing the body of the machine to pitch or tilt. The positioning system of the machine, such as a GPS antenna, will tilt with the machine. However, because the seed heads are pivotally attached the body of the machine, the position of the seed heads may not change relative to the ground. The database containing the path of the machine would indicate a change in direction, or location of the machine which is not accurate. A seed head may also encounter a rock which causes the seed head to pivot to one side temporarily. Therefore the position of the row of seedlings has changed relative to the path of the machine. Therefore simply using the path traversed by the planting machine is inadequate to determine the location of the seedlings.
If the location of the row of seedlings is known, then a cutting machine can be used instead of a push dozer, to detach the stalk from the plant seedlings. A cutting machine will reduce the number of root balls that were uprooted during harvesting. Additionally, the length of time the seedlings have been planted may be taken into account to predict the size of the rootballs. As the rootballs grow over the years, the placement of the groove cut by the ripper shank may be adjusted to account for the size of the root ball.
The present invention is aimed at solving one or more of the problems as set forth above.